The following includes information that may be useful in understanding the present invention(s). It is not an admission that any of the information provided herein is prior art, or material, to the presently described or claimed inventions, or that any publication or document that is specifically or implicitly referenced is prior art.
1. Field of the Invention
The present invention relates generally to the field of non-pneumatic tires and more specifically relates to non pneumatic vehicle tires and pneumatic vehicle tires with tread patterns.
2. Description of the Related Art
A tire is traditionally a ring-shaped covering that fits around a wheel's rim to protect it and enable better vehicle performance. Most tires, such as those for automobiles and bicycles, provide traction between the vehicle and the road while providing a flexible cushion that absorbs shock.
The fundamental materials of modern pneumatic tires are synthetic rubber, natural rubber, fabric and wire, along with carbon black and other chemical compounds. They consist of a tread and a body. The tread provides traction while the body provides containment for a quantity of compressed air. Before rubber was developed, the first versions of tires were simply bands of metal that fitted around wooden wheels to prevent wear and tear.
The tread is the part of the tire that comes in contact with the road surface. The portion that is in contact with the road at a given instant in time is the ‘contact patch’. The tread is a thick rubber, or rubber/composite compound formulated to provide an appropriate level of traction that does not wear away too quickly. The tread pattern is characterized by the geometrical shape of the grooves, lugs, voids and sipes. Grooves run circumferentially around the tire, and are needed to channel away water. Lugs are that portion of the tread design that contacts the road surface. Voids are spaces between lugs that allow the lugs to flex and evacuate water. Tread patterns feature non-symmetrical or non-uniform lug sizes circumferentially to minimize noise levels at discrete frequencies. Sipes are valleys cut across the tire, usually perpendicular to the grooves, which allow the water from the grooves to escape to the sides in an effort to prevent hydroplaning.
Treads are often designed to meet specific product marketing positions. High performance tires have small void ratios to provide more rubber in contact with the road for higher traction, but may be compounded with softer rubber that provides better traction, but wears quickly. Mud and snow tires are designed with higher void ratios to channel away rain (water) and mud, while providing better gripping performance. Specialized tires will always work better than general/all purpose/all weather tires when being used in the conditions the specialized tires are designed for.
Today, the majority of tires are pneumatic inflatable structures, comprising a doughnut-shaped body of cords and wires encased in rubber and generally filled with compressed air to form an inflatable cushion. Pneumatic tires are used on many types of vehicles, including cars, bicycles, motorcycles, scooters, trucks, buses, aircrafts, earthmovers, tractors, trailers, heavy equipments, carts, and lawnmowers. Metal tires are still used on locomotives and railcars.
Tire production starts with bulk raw materials such as rubber, carbon black, and chemicals and produces numerous specialized components that are assembled and cured. Many kinds of rubber are used, the most common being styrene-butadiene copolymer. The tire is an assembly of numerous components that are built up on a drum and then cured in a press under heat and pressure. Heat facilitates a polymerization reaction that cross-links rubber monomers to create long elastic molecules. These polymers create the elastic quality that permits the tire to be compressed in the area where the tire contacts the road surface and spring back to its original shape under high-frequency cycles. The present tire making process of pneumatic tires has many short-comings. Further, pneumatic tires are prone to rapid wear causing a large environmental footprint. Pneumatic tires may also be dangerous during blowouts and require maintenance on a steady basis. A reliable and safe solution is desirable.
Various attempts have been made to solve the above-mentioned problems such as those found in U.S. Pub. And Pub. Nos. 6,988,521; 3,901,300; 2012/0234444; 2010/0084910; 4,784,201; and 5,343,916. This art is representative of non-pneumatic tires. None of the above inventions and patents, taken either singly or in combination, is seen to describe the invention as claimed.
Ideally, solid rubber vehicle tires should provide safety and convenience and, yet would operate reliably and be manufactured at a modest expense. Thus, a need exists for reliable solid rubber (non-pneumatic) vehicle tires to avoid the above-mentioned problems.